Display device, camera, personal computer, and portable telephone

ABSTRACT

A light-emitting device having the quality of an image high in homogeneity is provided. A printed wiring board (second substrate) ( 107 ) is provided facing a substrate (first substrate) ( 101 ) that has a luminous element ( 102 ) formed thereon. A PWB side wiring (second group of wirings) ( 110 ) on the printed wiring board ( 107 ) is electrically connected to element side wirings (first group of wirings) ( 103, 104 ) by anisotropic conductive films ( 105   a   , 105   b ). At this point, because a low resistant copper foil is used to form the PWB side wiring ( 110 ), a voltage drop of the element side wirings ( 103, 104 ) and a delay of a signal can be reduced. Accordingly, the homogeneity of the quality of an image is improved, and the operating speed of a driver circuit portion is enhanced.

This application is a continuation of U.S. patent application Ser. No.09/732,049 filed Dec. 7, 2000, now U.S. Pat. No. 6,894,431.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a device having an element (hereinafterreferred to as luminous element) that is comprised of a luminousmaterial sandwiched between electrodes (the device will hereinafter bereferred to as light-emitting device), and to a method of manufacturingthe same. Specifically, the present invention relates to alight-emitting device using a luminous material that provides EL(Electro Luminescence) (hereinafter referred to as EL material).

2. Description of the Related Art

In recent years, development is proceeding in a light-emitting device(EL display device) using a luminous element that utilizes the ELphenomenon of a luminous material (hereinafter referred to as ELelement). The EL display device is a display device that uses a luminouselement which itself has a light-emitting ability, that is,self-emissive, and hence, unlike a liquid crystal display device, doesnot need a back light. In addition, the EL display device has meritssuch as a wide field of vision, light weight, and a low powerconsumption.

Such an El display device is constructed of a structure that has an ELelement composed of an anode, a cathode, and an EL material sandwichedtherebetween. By applying a voltage between the anode and the cathode tomake a current flow in the EL material, carriers re-couple, whereby theEL element emits light. Such a driving method is called a current drive.However, in the EL display device which has the current drive, there isa problem of a phenomenon in which a voltage drop (also referred to asan IR drop) caused by a wiring resistance occurs. This phenomenon isthat the voltage becomes lower as its distance from a power sourcebecomes farther even if it is the voltage of the same wiring. Thisproblem is particularly conspicuous when the wiring becomes long. Thus,it is a large obstacle in making the screen of the EL display devicelarger.

When the wiring is made of a material such as tantalum, tungsten, orsilicon, the EL display device is susceptible to the influence of thewiring resistance, which may become the cause of immensely reducing thehomogeneity of the quality of the image. In addition, in case of using alow resistant material such as aluminum or copper, when the draw-arounddistance is long, then the same thing can be observed, i.e., theaforementioned phenomenon will occur.

The above-mentioned problem will be explained here with reference toFIG. 2. Shown in FIG. 2 is a portion of a pixel portion of an activematrix EL display device. An

n

number of pixels denoted by A₁, A₂, . . . A_(n) are arranged in the upand down direction (vertical direction) of the diagram. Reference symbol201 denotes a gate wiring, 202 denotes a source wiring, and 203 denotesa current supply line. Furthermore, a switching TFT 204, a storagecapacitor 205, a current control TFT 206, and an EL element 207 areformed in a region that is surrounded by the gate wiring 201, the sourcewiring 202, and the current supply line 203.

At this point, the voltage of the current supply line 203 drops as thecurrent supply line 203 moves towards the bottom of the diagram due tothe influence of the voltage drop. That is, a voltage V₁ that was in theupper part of the pixel portion becomes a voltage V₂ in the lower partof the pixel portion, becoming a relationship of V₁>V₂. This influencebecomes more conspicuous as the area of the pixel portion (image displayregion) is made larger.

As a result, in case of making the EL elements of each of the pixelsemit light in the same brightness, the pixel denoted by A₁ and the pixeldenoted by A₂ will emit light in about the same brightness. However, thebrightness of the light emitted by the pixel denoted by A_(n) declinescompared with the pixel denoted by A₁ and the pixel denoted by A₂. Thereason for this originates in that the voltage applied to the EL elementof the pixel denoted by A_(n) has declined due to the voltage drop.

Further, the influence of such voltage drop is imparted not only to thecurrent supply line 203 but also to the gate wiring 201 and the sourcewiring 202. In other words, there is a concern that the gate wiring 201may not be able to open a gate of the switching TFT 204 because of thevoltage drop. In addition, the source wiring 202 becomes incapable ofapplying a desired voltage to a gate of the current control TFT 206 dueto the voltage drop, leading to a fear that the brightness of the ELelement will change or that the EL element will not emit light.

Thus, the transmission of a desired voltage becomes impossible becauseof the voltage drop which originates in the wiring resistance.

Consequently, a drawback in which there is a considerable loss in thehomogeneity of the quality of the image in the pixel portion occurs.Attempts such as contriving to apply a voltage to both ends of thewiring have been made in order to improve the above problem. However,because the wiring is drawn around longer, as a result, the influence ofthe voltage drop cannot be ignored.

In case of manufacturing a monolithic type light-emitting device inwhich a driver circuit portion (typically including a gate drivercircuit and a source driver circuit) is integrated on the samesubstrate, the wiring resistance of a wiring that is drawn aroundbetween the driver circuit portion and an input terminal of an electricsignal becomes a problem. The wiring resistance induces a delay of theelectric signal, and therefore there is a concern that the operatingspeed of the gate driver circuit and the source driver circuit will bereduced.

Thus, drawbacks such as the considerable loss of the homogeneity of thequality of the image and the extreme decline in the operating speed ofthe driver circuit portion due to the voltage drop which originates inthe wiring resistance and the delay of a signal occur.

Such a problem becomes a particularly conspicuous problem in alight-emitting device having a large screen that is several tens inchesin diagonal.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above, and thereforehas an object to provide a light-emitting device that has a homogenizedquality of image by suppressing an influence of a voltage drop whichoriginates in the above-mentioned wiring resistance. Further, anotherobject of the present invention is to suppress a delay of a wiring whichelectrically connects a driver circuit portion and an input/outputterminal to thereby enhance the operating speed of the driver circuitportion.

The light-emitting device of the present invention is constituted of asubstrate having a luminous element formed thereon (hereinafter referredto as element-formed substrate or a first substrate) and a hardenedlarge printed wiring board (PWB: Printed Wiring Board), which areelectrically connected by a conductor (anisotropic conductive film or abump), and is characterized in that the resistance of each of thewirings (first group of wirings) formed on the element-formed substrateis reduced.

It is to be noted that the hardened large printed wiring board(hereinafter referred to as printed wiring board or a second substrate)indicates a printed wiring board that has a level of hardness which doesnot bend or curve to some amount of impact.

Typically, the hardened large printed wiring board refers to a printedwiring board that is formed of a material selected from a glass clothepoxy, glass cloth heat-resistant epoxy, ceramic, alumina, paper-basedphenol, or paper-based epoxy. In addition, it is also possible to use atransmissive glass substrate, a quartz substrate, or a plasticsubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects and features of the present invention willbe more apparent from the following description taken in conjunctionwith the accompanying drawings:

FIGS. 1A and 1B are diagrams showing a cross-sectional structure and atop structure of a light-emitting device, respectively;

FIG. 2 is a diagram illustrating the change in brightness of a pixel;

FIGS. 3A and 3B are diagrams showing top structures of a light-emittingdevice, and FIG. 3C is a diagram showing a cross-sectional structurethereof;

FIGS. 4A and 4B are diagrams showing a top structure and across-sectional structure of an EL display device, respectively;

FIGS. 5A and 5B are diagrams showing a top structure and across-sectional structure of an EL display device, respectively;

FIG. 6 is a diagram showing a cross-sectional structure of an EL displaydevice;

FIG. 7 is a diagram showing a cross-sectional structure of an EL displaydevice;

FIGS. 8A to 8F are views showing electric equipments of the presentinvention; and

FIGS. 9A and 9B are views showing electric equipments of the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The cross-sectional view of the light-emitting device of the presentinvention is shown in FIG. 1A, and the top view thereof is shown in FIG.1B. Note that the cross-sectional view taken along the line A–A′ of FIG.1B corresponds to FIG. 1A.

In FIG. 1A, reference symbol 101 denotes a substrate having a luminouselement 102 (typically an EL element or a semiconductor diode element)formed thereon. Wirings 103 and 104 for transmitting an electric signal(hereinafter referred to as element side wiring) to the luminous element102 are formed on the substrate 101. These components correspond to theabove-mentioned element-formed substrate. It is to be noted that a glasssubstrate, a quartz substrate, a plastic substrate, a silicon substrate,a ceramic substrate, or a metallic substrate may be used as thesubstrate 101.

A printed wiring board 107 is electrically connected to the substrate101 via conductors 105 a and 105 b that are provided on the wirings 103and 104 of the element-formed substrate. It is to be noted thatreference symbols 106 a and 106 b denote sealing agents for bonding theelement-formed substrate 101 and the printed wiring board 107 together.

Furthermore, a group of wirings (second group of wirings) are formed onthe front surface, the back surface or the interior of the printedwiring board 107. When the wirings are formed in two or more differentlayers, it is referred to as a multi-layered wiring (or a laminationwiring) in the present specification. On the other hand, when one layerof wiring is formed in either the front surface, the back surface, orthe interior, then it is referred to as a single-layered wiring in thepresent specification.

In the present invention, the printed wiring board 107 may have eitherthe multi-layered wiring or the single-layered wiring.

At this point, an anisotropic conductive film, a conductive paste or abump can be used as the conductors 105 a and 105 b. As the bump,typically, a solder bump, a metal bump, a nickel bump, or a copper bumpcan be used. In addition, resin having metallic particles such as silverand nickel dispersed therein can be used as the conductive paste.

An FPC (Flexible Printed Circuit) 108 is attached to a terminal portionof the printed wiring board 107. Further, a wiring 110 for transmittingan electric signal, which was transmitted to an anisotropic conductivefilm 109, to the conductors 105 a and 105 b is formed to a thickness ofbetween 1 and 20 μm (hereinafter referred to as PWB side wiring or thesecond group of wirings). Typically, a pattern formed of a copper foil,a gold foil, a silver foil, a nickel foil, or an aluminum foil is usedas the PWB side wiring 110. Note that though the FPC is a printed wiringboard in a broad sense, it is not included in the definition of theprinted wiring board in the present invention.

In the light-emitting device of the present invention incorporating theabove-mentioned structure, an electric signal transmitted to the FPC 108is transmitted to the conductors 105 a and 105 b by the PWB side wiring110, and then the signal can be transmitted to the luminous element 102via the element side wirings 103 and 104. At this point, because the PWBside wiring 110 is made of an extremely low resistant wiring, thevoltage drop which originates in the wiring resistance can be immenselysuppressed, thereby making it possible to transmit nearly equivalentelectric signals to the element side wirings 103 and 104. Similarly, thewiring resistance of the PWB side wiring 110 is small, and therefore,the delay of a signal is largely suppressed. Consequently, it ispossible to improve the drawback of the reduction in the operating speedof the driver circuit.

Further, a characteristic of the present invention is that a materialselected from a glass cloth epoxy, glass cloth heat-resistant epoxy,ceramic, alumina, paper-based phenol, or paper-based epoxy is used asthe material of the printed wiring board 107 so that the printed wiringboard 107 has an impact-resistant property. As a result, it becomespossible to protect the luminous element from external impact, whereby ahighly reliable light-emitting device can be attained.

A case of manufacturing an EL display device by employing the presentinvention will be explained in Embodiment Mode of the present invention.The top views of the EL display device manufactured by employing thepresent invention is shown in FIGS. 3A and 3B.

Note that in Embodiment Mode, the top views of the EL display device areshown in FIGS. 3A and 3B, and the cross-sectional view thereof is shownin FIG. 3C. FIG. 3C is a cross-sectional view taken along the lineA–A′in the top views of FIGS. 3A and 3B. Further, a printed wiring boardis formed from a two-layered structure in Embodiment Mode, and therespective layers are shown in FIGS. 3A and 3B.

In FIG. 3A, reference symbol 300 denotes a first printed wiring board,and a wiring 301 for aiding a current supply line (hereinafter referredto as current supply auxiliary line) is formed thereon. In the presentspecification, the current supply line is a wiring for supplying acurrent, which flows to an EL element, to each EL element, and thewiring for aiding the current supply line is a wiring that is connectedin parallel to the current supply line in order to reduce the apparentwiring resistance of the current supply line. The wiring for aiding thecurrent supply line can be made of a metallic film of copper, silver,gold, aluminum or nickel, or an alloy film containing as a maincomponent a material selected from copper, silver, gold, aluminum, ornickel. Also, the wiring for aiding the current supply line can beformed into a layered structure made of a metallic film that is made oftwo or more different elements selected from copper, silver, gold,aluminum and nickel.

Further, a dotted line denoted by reference symbol 302 is a sourcedriver circuit, dotted lines denoted by reference symbols 303 a and 303b are gate driver circuits, and a dotted line denoted by referencesymbol 304 is a pixel portion. These driver circuits and the pixelportion are formed on an element-formed substrate 330 (refer to FIG.3C). In addition, a thick dotted line denoted by reference symbol 305 isa current supply line that is formed on the element-formed substrate330. In a contact portion 306 at this point, the current supplyauxiliary line 301 is electrically connected to a conductor 307, andfurther electrically connected to the current supply line 305 via theconductor 307.

Thus, the current supply auxiliary line 301 that is made of a lowresistant material such as a copper foil is formed on the first printedwiring board 300. The current supply auxiliary line 301 is electricallyconnected to the current supply line 305, that is formed on theelement-formed substrate 330, via the contact portion 306. Accordingly,it is possible to make the electric potential equal in any position ofthe current supply line 305, and therefore, the voltage drop of thecurrent supply line 305 can be substantially suppressed.

In FIG. 3B, reference symbol 310 denotes a second printed wiring board,and a wiring 311 for aiding a gate control wiring (hereinafter referredto as gate control auxiliary line) is formed thereon. In the presentspecification, the gate control wiring is a wiring for transmitting apower source signal of the gate driver circuit, a clock signal, or astart signal, and the wiring for aiding the gate control wiring is awiring that is connected in parallel to the gate control wiring in orderto reduce the apparent wiring resistance of the gate control wiring.

Further, the thick dotted line denoted by reference symbol 312 is a gatecontrol wiring that is formed on the element-formed substrate. At thispoint, the gate control auxiliary line 311 is electrically connected toa conductor 314 via a contact portion 313, and then further electricallyconnected to a gate control wiring 315 via the conductor 314.

Thus, the gate control auxiliary line 311 that is made of a lowresistant material such as a copper foil is formed on the second printedwiring board 310. The gate control auxiliary line 311 is electricallyconnected to the gate control wiring 312 that is formed on theelement-formed substrate 330 via the contact portion 313. Accordingly,it is possible to make the electric potential equal in any position ofthe gate control wiring 312, and therefore, the voltage drop of the gatecontrol wiring 312 can be substantially suppressed.

In Embodiment Mode of the present invention, the first printed wiringboard 300 and the second printed wiring board 310 are first adhered toeach other (denoted as printed wiring board 320), and then the adheredboards are bonded with the element-formed substrate 330 by using asealing agent 331. Either the first printed wiring board 300 or thesecond printed wiring board 310 is electrically connected to theelement-formed substrate 330 through the conductor 307 or 314. It is tobe noted that there is no limit to the position of providing theconductors 307 and 314.

In Embodiment Mode, the gap between the printed wiring board 320 and theelement-formed substrate 330 is prescribed by the height of theanisotropic conductive film, conductive paste or bump. It is desirablethat the gap is formed between 5 μm and 1 mm (preferably between 10 and100 μm). If the gap is too narrow, then the printed wiring board 320 andthe luminous element may be in contact with each other. On the otherhand, if the gap is too wide, then it becomes difficult for theanisotropic conductive film, conductive paste, or bump to secure thegap. Note that a spacer or a filler used in a liquid crystal may be usedto secure the gap.

Furthermore, an inert gas (preferably argon gas, neon gas, nitrogen gas,or helium gas) or resin may be filled in an airtight space 321 betweenthe element-formed substrate 330 and the printed wiring board 320. Asthe resin, ultraviolet cured resin, thermosetting resin, silicone resin,epoxy resin, acrylic resin, polyimide resin, phenol resin, PVC(polyvinyl chloride), PVB (polyvinyl butylal), or EVA (ethylenevinylacetate) may be used.

It is effective to provide a moisture absorbent material (typicallybarium oxide or cesium oxide) together with the inert gas or the resinin the interior of the airtight space 321.

An important point in Embodiment Mode of the present invention is that alow resistant wiring pattern provided in the printed wiring board iselectrically connected to the current supply line 305 and the gatecontrol wiring 312 which readily become the wiring resistant problem.Thus, the occurrence of the voltage drop caused by the wiring resistanceof the current supply line 305 and the gate control wiring 312 can besuppressed, whereby an EL display device that may perform a homogeneousimage display can be manufactured.

Embodiment 1

In Embodiment 1, an explanation will be made with reference to FIGS. 4Aand 4B on an active matrix EL display device that is manufactured byemploying the present invention. FIG. 4A is a top view of anelement-formed substrate (denoted by reference symbol 400 in FIG. 4B)having an EL element formed thereon. Indicated by the dotted lines,reference symbol 401 denotes a source driver circuit, 402 denotes a gatedriver circuit, and 403 denotes a pixel portion.

Further, reference symbol 404 denotes a printed wiring board, and a PWBside wiring 405 is formed thereon. The dotted line indicated byreference symbol 406 denotes a first sealing member, and in the innerside surrounded by the first sealing member 406, resin (denoted byreference symbol 407 in FIG. 4B) is provided between the printed wiringboard 404 and the element-formed substrate 400.

It is to be noted that barium oxide (denoted by reference symbol 408 inFIG. 4B) is used as the moisture absorbent material doped into the resin407.

Reference symbol 409 denotes a contact portion which electricallyconnects the PWB side wiring 405 and connecting wirings 410 a to 410 cthat are formed on the element-formed substrate 400. An electric signalsuch as a video signal or a clock signal inputted from an FPC (FlexiblePrinted Circuit) 411, which serves as a connecting terminal with anexternal device, is transmitted to the PWB side wiring 405, and then istransmitted to the current supply line via the contact portion 409.

A cross-sectional view corresponding to the cross-section taken alongthe line A–A′of FIG. 4A is shown in FIG. 4B. It is to be noted that inFIGS. 4A and 4B, the same reference symbols are used to denote the samecomponents. As shown in FIG. 4B, the pixel portion 403 and the sourceside driver circuit 401 are formed on the substrate 400. The pixelportion 403 is formed of a plurality of pixels each including a TFT 431for controlling the current that flows to an EL element (hereinafterreferred to as current control TFT) and a pixel electrode 432electrically connected to the drain of the current control TFT 431.Further, the source side driver circuit 401 is formed using a CMOScircuit in which an N channel TFT 433 and a P channel TFT 434 arecombined complementarily.

The pixel electrode 432 is formed of a transparent conducting film (afilm made of a compound of indium oxide and tin oxide in Embodiment 1)and functions as an anode of the EL element. An insulating film 435 isformed on both ends of the pixel electrode 432 where a light-emittinglayer 436 a luminescing red, a light-emitting layer 436 b luminescinggreen, and a light-emitting layer luminescing blue (not shown in thedrawing) are further formed.

A light shielding conductive film (an alloy film of lithium and aluminumin Embodiment 1) is used to form a cathode 437 of the EL element that isfurther formed thereon.

Regarding the film deposition method of the light-emitting layers 436 aand 436 b, any known method may be used, and an organic material or aninorganic material can be used as the material for forming thelight-emitting layers. The structure of the light-emitting layer do nothave to only be the light-emitting layer, but may be a laminationstructure in which an electron injection layer, an electrontransportation layer, a hole transportation layer, and a hole injectionlayer are combined.

In case of Embodiment 1, the cathode 437 also functions as a commonwiring shared by all the pixels, and is electrically connected to theconnecting wirings 410 a to 410 c. The connecting wirings 410 a to 410 care electrically connected to the PWB side wiring 405 by anisotropicconductive films 440 a to 440 c. Furthermore, because the PWB sidewiring 405 is electrically connected to the FPC 411, as a result, theconnecting wirings 410 a to 410 c become electrically connected to theFPC 411.

Note that in Embodiment 1, the first sealing member 406 is formed byusing a dispenser or the like, and a spacer (not shown) is sprayed tobond the first sealing member 406 to the printed wiring board 404. Theresin 407 is then filled into a space surrounded by the element-formedsubstrate 400, the printed wiring board 404, and the first sealingmember 406. Although resin doped with barium oxide as the moistureabsorbent material is used in Embodiment 1, the barium oxide can besealed inside the resin in massive distributions. In addition, as thematerial of the not shown spacer, a moisture absorbent material may beused.

Next, after curing the resin 407 by ultraviolet irradiation or heatapplication, an opening portion (not shown) formed in the first sealingmember 406 is closed. Then, a second sealing member 412 is disposed soas to cover a portion of the first sealing member 406, the printedwiring board 404, and the FPC 411. The second sealing member 412 may beformed of the same material as the first sealing member 406.

By sealing the EL element within the resin 407 using the method asdescribed above, the EL element is completely cut off from externalenvironment, and the invasion by substances such as moisture and oxygenfrom the outside which accelerate the oxidation degradation of theorganic material thus can be prevented. Accordingly, an EL displaydevice with high reliability can be manufactured.

Further, the occurrence of the voltage drop caused by the wiringresistance of the current supply line and the gate control wiringprovided on the element-formed substrate can be suppressed by employingthe present invention, whereby an EL display device that may perform ahomogeneous image display can be manufactured.

Embodiment 2

In Embodiment 2, an explanation will be made with reference to FIGS. 5Aand 5B on a passive matrix EL display device that is manufactured byemploying the present invention. It is to be noted that FIG. 5A is a topview thereof and FIG. 5B is a cross-sectional view thereof taken alongthe line A–A′of FIG. 5A.

In FIG. 5B, reference symbol 501 denotes an element-formed substratemade of plastic, and reference symbol 502 denotes an a node made of acompound of indium oxide and zinc oxide. In Embodiment 2, the anode 502is formed by the evaporation method. Though not shown in FIGS. 5A and5B, it is to be noted that a plurality of anodes are arranged in stripeshapes in a parallel direction in a defined space.

An insulating film 503 is formed such that it is orthogonal to theplurality of anodes 502 arranged in stripe shapes. In addition, theinsulating film 503 is also provided in the gaps of the anodes 502 inorder to insulate each of the anodes 502 separately. Therefore, theinsulating film 503 is patterned into matrix when observed from the top.

Further, a bank 504 made of resin is formed on the insulating film 503.The bank 504 is formed in a perpendicular direction in the space suchthat it is orthogonal to the anodes 502. The shape of the bank 504 isprocessed into an inverted triangle (inverted taper shape). Note thatthe structure may be a two-layered structure where the upper layerhaving an eaves-shape is on the lower layer.

Thereafter, a light-emitting layer 505 and a cathode 506 made of analuminum alloy are formed in succession. It is preferable tosuccessively form both the light-emitting layer 505 and the cathode 506under a vacuum or inert atmosphere because the light-emitting layer 505is easily affected by moisture and oxygen.

The light-emitting layer 505 may be formed of any known material.

However, a polymer-based organic material is preferred from theviewpoint of an easy and simple film deposition. Also, it is preferablethat the cathode 506 is formed by the evaporation method.

The light-emitting layer 505 and the cathode 506 are both formed in thegrooves which are formed by the bank 504. Both are arranged in stripeshapes in a perpendicular direction in the defined space.

Though not shown in the figures, it is effective to provide a holetransportation layer or a hole injection layer as a buffer layer betweenthe light-emitting layer 505 and the cathode 506. Material such ascopper pthalocyanine, polythiophene, or PEDOT can be used as the holeinjection layer.

Thus, an EL element is formed on the element-formed substrate 501 by theabove described method. Note that because the bottom electrode serves asa transmissive anode in Embodiment 2, the light generated in thelight-emitting layer 505 is irradiated in a direction towards the bottomsurface (in the direction towards the element-formed substrate 501) inthe defined space.

The anodes 502 are electrically connected to a PWB side wiring 511 thatis formed on a printed wiring board 510 by anisotropic conductive films508 a and 508 b which are provided inside a first sealing member 507. InEmbodiment 2, the PWB side wiring 511 is a three-layered structure madeup of a wiring 511 a provided on the front surface of the printed wiringboard 510, a wiring 511 b provided in the interior thereof, and a wiring511 c provided on the back surface thereof. The materials cited in theexplanation of FIG. 1 can be used as the material to form the printedwiring board 510.

At this point, as shown in FIG. 5A, the wiring 511 a provided on thefront surface of the printed wiring board 510 and the wiring 511 bprovided in the interior thereof are formed such that they areorthogonal to each other. The wiring 511 a provided on the front surfaceof the printed wiring board 510 is electrically connected to the anodes502, and the wiring 511 c provided on the back surface thereof iselectrically connected to the cathode 506.

Further, the wiring 511 a provided on the front surface of the printedwiring board 510 is electrically connected to an FPC 512 to therebytransmit a signal from an external equipment.

In Embodiment 2, the space between the element-formed substrate 501 andthe printed wiring board 510 is provided with a resin 513 and a moistureabsorbent material 514 that is doped into the resin 513 to therebyprotect the EL element from moisture and oxygen. Of course, the spacemay be filled with inert gas instead of filling the space with theresin. In addition, a second sealing member 515 is provided so as tocover the entire printed wiring board 510 to thereby suppress thedeterioration of the EL element.

By sealing the EL element within the resin 513 using the method asdescribed above, the EL element is completely cut off from externalenvironment, and the invasion by substances such as moisture and oxygenfrom the outside which accelerate the oxidation degradation of theorganic material thus can be prevented. Accordingly, an EL displaydevice with high reliability can be manufactured.

Further, the occurrence of the voltage drop caused by the wiringresistance of the anodes and cathodes provided on the element-formedsubstrate can be suppressed by employing the present invention, wherebyan EL display device that may perform a homogeneous image display can bemanufactured.

Embodiment 3

Shown in Embodiment 3 is a modified example of the structure of the ELdisplay device described in Embodiment 1. The description thereof willbe made with reference to FIG. 6. Structures of a TFT and an EL elementformed on the element-formed substrate 400 are the same as those ofFIGS. 4A and 4B. Therefore, only different components will be denotedwith reference symbols and explained.

Upon forming a structure similar to that of Embodiment 1 up to theformation of the cathode 437, a passivation film 601 is further formedto a thickness of 50 to 500 nm (preferably between 300 and 400 nm) tocover the cathode 437. As the passivation film 601, a tantalum oxidefilm, a silicon nitride film, a silicon oxide film, a silicon oxidenitride film, or a lamination film of a combination thereof may be used.It is preferable that the film deposition thereof is performed at atemperature of 150° C. or less by vapor-phase deposition such that theEL element will not deteriorate.

The sealing of the EL element is completed by the passivation film 601in Embodiment 3. That is, the EL element is protected from externalsubstances such as moisture and oxygen by the passivation film 601, andhence Embodiment 3 is characterized in that the reliability of the ELdisplay device is enhanced. Accordingly, though the structure shown inFIGS. 4A and 4B is one in which the EL element is sealed by the resin407 for protection from external substances, in Embodiment 3, there isno need to particularly perform such sealing. As a result, the structureof the EL display device can be simplified.

At this point, anisotropic conductive films 602 a and 602 b are not onlyelectrically connected to the connecting wirings 410 a to 410 c and aPWB side wiring 604 that is formed on a printed wiring board 603, butalso carry the role of a spacer for determining the gap between theelement-formed substrate 400 and the printed wiring board 603. Ofcourse, a separate spacer may be provided.

By sealing the EL element with the passivation film 601 using the methodas described above, the EL element is completely cut off from externalenvironment, and the invasion by substances such as moisture and oxygenfrom the outside which accelerate the oxidation degradation of theorganic material thus can be prevented. Accordingly, an EL displaydevice with high reliability can be manufactured.

Further, the occurrence of the voltage drop caused by the wiringresistance of the current supply line and the gate control wiringprovided on the element-formed substrate can be suppressed by employingthe present invention, whereby an EL display device that may perform ahomogeneous image display can be manufactured.

Note that the constitution of Embodiment 3 may be combined with theconstitution of Embodiment 1.

Embodiment 4

Shown in Embodiment 4 is a modified example of the structure of the ELdisplay device described in Embodiment 1. The description thereof willbe made with reference to FIG. 7. Structures of a TFT and an EL elementformed on the element-formed substrate 400 are basically the same asthose of FIGS. 4A and 4B. Therefore, only different components will bedenoted with reference symbols and explained.

In Embodiment 4, the structure of the EL element is a reversed one fromthat of FIGS. 4A and 4B. A light shielding conductive film (an aluminumalloy film in Embodiment 4) is used as a pixel electrode (cathode) 701,and a transparent conductive film (a compound film of indium oxide andzinc oxide in Embodiment 4) is used as an anode 702. Thus, the directionof the light emitted is a direction towards the upper part of thediagram (direction indicated by an arrow).

Upon completion of the EL element, a covering member 704 is bonded by afirst sealing member 703, and the inside thereof is provided with aresin 706 that is doped with a moisture absorbent material 705. Atransmissive material can be used as the covering member 704, and aresin film, a resin substrate, a plastic substrate, a glass substrate,or a quartz substrate may be used.

Next, a via hole is formed from the back surface of the element-formedsubstrate 400 to thereby form connecting wirings 707 a and 707 b. Theconnecting wirings 707 a and 707 b are further electrically connected toa PWB side wiring 710 that is formed on a printed wiring board 709 viabumps 708 a and 708 b which are made of gold, solder, or nickel. The PWBside wiring 710 is electrically connected to an FPC 711. It is to benoted that reference symbol 712 denotes a resin for bonding theelement-formed substrate 400 and the printed wiring board 709. However,it may be a structure without the provision of the resin 712.

The occurrence of the voltage drop caused by the wiring resistance ofthe current supply line and the gate control wiring provided on theelement-formed substrate can be suppressed by employing the structure ofEmbodiment 4, whereby an EL display device that may perform ahomogeneous image display can be manufactured.

Embodiment 5

Examples of the light-emitting device employing the EL element wereexplained in Embodiments 1 through 4. However, the present invention mayalso be employed in an EC (Electro Chromic) display device, a fieldemission display (FED) or a light-emitting device having alight-emitting diode that employs a semiconductor.

Embodiment 6

The light-emitting device formed by implementing the present inventionhas superior visibility in bright locations in comparison to a liquidcrystal display device because it is a self-emissive type device, andmoreover its angle of vision is wide. Accordingly, it can be used as adisplay portion for various electronic equipment.

For example, for appreciation of TV broadcasts by large screen, it isappropriate to use a display of the present invention incorporating thelight-emitting device in its casing and having a diagonal equal to 20 to60 inches.

Note that all displays for exhibiting information such as a personalcomputer display, a TV broadcast reception display, or an advertisementdisplay are included as the display incorporating a light-emittingdevice in its casing. Further, the light emitting device of the presentinvention can be used as a display portion of the other variouselectronic equipment.

The following can be given as examples of such electronic equipment: avideo camera; a digital camera; a goggle type display (head mounteddisplay); a car navigation system; an audio reproducing device (such asa car audio system, an audio component system); a notebook personalcomputer; a game equipment; a portable information terminal (such as amobile computer, a mobile telephone, a mobile game equipment or anelectronic book); and an image playback device provided with a recordingmedium (specifically, a device which performs playback of a recordingmedium and is provided with a display which can display those images,such as a digital video disk (DVD)). In particular, because portableinformation terminals are often viewed from a diagonal direction, thewideness of the angle of vision is regarded as very important. Thus, itis preferable that the EL display device is employed. Examples of theseelectronic equipment are shown in FIGS. 8 and 9.

FIG. 8A is a display incorporating a light-emitting device in itscasing, containing a casing 2001, a support stand 2002, and a displayportion 2003. The present invention can be used in the display portion2003. Since the display is a self-emissive type device without the needof a backlight, its display portion can be made thinner than a liquidcrystal display device.

FIG. 8B is a video camera, containing a main body 2101, a displayportion 2102, a voice input portion 2103, operation switches 2104, abattery 2105, and an image receiving portion 2106. The light emittingdevice of the present invention can be used in the display portion 2102.

FIG. 8C is a portion of a head fitting type EL display (right side),containing a main body 2201, a signal cable 2202, a head fixing band2203, a display portion 2204, an optical system 2205, and a lightemitting device 2206. The present invention can be used in the lightemitting device 2206.

FIG. 8D is an image playback device (specifically, a DVD playbackdevice) provided with a recording medium, containing a main body 2301, arecording medium (such as a DVD) 2302, operation switches 2303, adisplay portion (a) 2304, and a display portion (b) 2305. The displayportion (a) is mainly used for displaying image information, and theimage portion (b) is mainly used for displaying character information,and the light emitting device of the present invention can be used inthese image portions (a) and (b). Note that domestic game equipment isincluded as the image playback device provided with a recording medium.

FIG. 8E is a mobile computer, containing a main body 2401, a cameraportion 2402, an image receiving portion 2403, operation switches 2404,and a display portion 2405. The light emitting device of the presentinvention can be used in the display portion 2405.

FIG. 8F is a personal computer, containing a main body 2501, a casing2502, a display portion 2503, and a keyboard 2504. The light emittingdevice of the present invention can be used in the display portion 2503.

Note that in the future if the emission luminance becomes higher, theprojection of light including outputted images can be enlarged bylenses, optical fiber, or the like. Then it will become possible to usethe light emitting device in a front type or a rear type projector.

The emitting portion of the light emitting device consumes power, andtherefore it is preferable to display information so as to have theemitting portion become as small as possible. Therefore, when using thelight emitting device in a display portion which mainly displayscharacter information, such as a portable information terminal, inparticular, a portable telephone and an audio reproducing device, it ispreferable to drive it by setting non-emitting portions as backgroundand forming character information in emitting portions.

FIG. 9A is a portable telephone, containing a main body 2601, a voiceoutput portion 2602, a voice input portion 2603, a display portion 2604,operation switches 2605, and an antenna 2606. The light emitting deviceof the present invention can be used in the display portion 2604. Notethat by displaying white characters in a black background in the displayportion 2604, the power consumption of the portable telephone can bereduced.

FIG. 9B is an audio reproducing device, specifically a car audio system,containing a main body 2701, a display portion 2702, and operationswitches 2703 and 2704. The light emitting device of the presentinvention can be used in the display portion 2702. Furthermore, an audioreproducing device for a car is shown in Embodiment 6, but it may alsobe used for a mobile type and a domestic type of audio reproducingdevice. Note that by displaying white characters in a black backgroundin the display portion 2704, the power consumption can be reduced. Thisis particularly effective in a mobile type audio reproducing device.

The range of applications of the present invention is thus extremelywide, and it is possible to apply the present invention to electronicequipment in all fields. Furthermore, any constitution of the lightemitting device shown in Embodiments 1 to 6 may be employed in theelectronic equipment of this embodiment.

Embodiment 7

In the case that an electric equipment having a light-emitting deviceaccording to the present invention as a display portion is usedoutdoors, of course the display portion is viewed sometimes when it isdark and sometimes when it is light. Though, when it is dark, what isdisplayed can be sufficiently recognized even if the luminance is not sohigh, when it is light, what is displayed may not be recognized if theluminance is not high.

With regard to a light-emitting device, since the luminance varies inproportion to the current or the voltage for operating the element, ifthe luminance is required to be higher, the power consumption has to beincreased accordingly. However, if the level of the luminance of lightemission is adjusted to be so high, when it is dark, the display is muchbrighter than needed with the power consumption being unnecessarilylarge.

In order to provide for such a case, it is effective to provide alight-emitting device according to the present invention with a functionto sense with a sensor the brightness of the environment and to adjustthe luminance of light emission according to the degree of thebrightness. More specifically, the luminance of light emission is madehigh when it is light, while the luminance of light emission is made lowwhen it is dark. As a result, a light-emitting device which can preventthe power consumption from increasing and which does not make the userfeel fatigued can be realized.

It is to be noted that, as such a sensor for sensing the brightness ofthe environment, a CMOS sensor or a CCD (charge-coupled device) can beused. Such a CMOS sensor may be conventionally integrated on a substratewhere a light emitting element is formed, or a semiconductor chip may beattached to the outside. Further, a semiconductor chip having such a CCDformed thereon may be attached to a substrate where a light emittingelement is formed, or a part of the electric equipment having thelight-emitting device as its display portion may be structured to beprovided with the CCD or the CMOS sensor.

A control circuit for changing the current or the voltage for operatingthe light emitting element in response to a signal obtained by thesensor for sensing the brightness of the environment is provided, bywhich the luminance of light emission of the light-emitting element canbe adjusted according to the brightness of the environment.

It is to be noted that such adjustment may be made either automaticallyor manually.

It is to be noted that the structure of the present embodiment can beimplemented in any electric equipment described in Embodiment 6.

In the active matrix type or the passive type of light-emitting device,the delay of a signal and the voltage drop due to a wiring resistanceare reduced to thereby enhance the operating speed of the driver circuitportion and improve the homogeneity of the quality of the image in thepixel portion.

1. A display device comprising: a first substrate; a light emittingelement over the first substrate comprising: a first electrode; a secondelectrode adjacent to the first electrode; and a light emitting materialinterposed between the first electrode and the second electrode; acurrent supply line over the first substrate, electrically connected tothe first electrode; a second substrate; and an auxiliary wiringadjacent to the second substrate, wherein the auxiliary wiring iselectrically connected to the first electrode via the current supplyline in a first connecting portion, and wherein the auxiliary wiring iselectrically connected to the first electrode via the current supplyline in a second connecting portion.
 2. A display device according toclaim 1, wherein the auxiliary wiring comprises a metal selected fromthe group consisting of a copper, a silver, a gold, an aluminum and anickel.
 3. A display device according to claim 1, wherein a part of theauxiliary wiring is located in the second substrate.
 4. A display deviceaccording to claim 1, wherein the auxiliary wiring is electricallyconnected to the current supply line via a conductive material.
 5. Adisplay device comprising: a first substrate; a light emitting elementover the first substrate: a first electrode; a second electrode adjacentto the first electrode; and a light emitting material interposed betweenthe first electrode and the second electrode; a current supply line overthe first substrate, electrically connected to the first electrode; aninsulating layer over the light emitting element; a second substrate;and an auxiliary wiring adjacent to the second substrate, wherein theauxiliary wiring is electrically connected to the first electrode viathe current supply line, and wherein the insulating layer is locatedbetween the current supply line and the auxiliary wiring.
 6. A displaydevice according to claim 5, wherein the auxiliary wiring comprises ametal selected from the group consisting of a copper, a silver, a gold,an aluminum and a nickel.
 7. A display device according to claim 5,wherein a part of the auxiliary wiring is located in the secondsubstrate.
 8. A display device according to claim 5, wherein theauxiliary wiring is electrically connected to the current supply linevia a conductive material.
 9. A display device according to claim 5,wherein the insulating layer is a resin material.
 10. A display deviceaccording to claim 9, wherein the resin material comprises a moistureabsorbent material.
 11. A display device according to claim 5, whereinthe insulating layer is a passivation film.
 12. A display devicecomprising: a first substrate; a light emitting element over the firstsubstrate: a first electrode; a second electrode adjacent to the firstelectrode; and a light emitting material interposed between the firstelectrode and the second electrode; a current supply line over the firstsubstrate, electrically connected to the first electrode; an insulatinglayer over the light emitting element; a second substrate; and anauxiliary wiring adjacent to the second substrate, wherein the auxiliarywiring is electrically connected to the first electrode via the currentsupply line, and wherein the first substrate is located between thecurrent supply line and the auxiliary wiring.
 13. A display deviceaccording to claim 12, wherein the auxiliary wiring comprises a metalselected from the group consisting of a copper, a silver, a gold, analuminum and a nickel.
 14. A display device according to claim 12,wherein a part of the auxiliary wiring is located in the secondsubstrate.
 15. A display device according to claim 12, wherein theauxiliary wiring is electrically connected to the current supply linevia a conductive material.
 16. A display device according to claim 12,wherein the insulating layer is a resin material.
 17. A display deviceaccording to claim 16, wherein the resin material comprises a moistureabsorbent material.
 18. A display device according to claim 12, whereinthe insulating layer is a passivation film.
 19. A camera comprising adisplay device comprising: a first substrate; a light emitting elementover the first substrate: a first electrode; a second electrode adjacentto the first electrode; and a light emitting material interposed betweenthe first electrode and the second electrode; a current supply line overthe first substrate, electrically connected to the first electrode; asecond substrate; and an auxiliary wiring adjacent to the secondsubstrate, wherein the auxiliary wiring is electrically connected to thefirst electrode via the current supply line in a first connectingportion, and wherein the auxiliary wiring is electrically connected tothe first electrode via the current supply line in a second connectingportion.
 20. A camera comprising a display device according to claim 19,wherein the auxiliary wiring comprises a metal selected from the groupconsisting of a copper, a silver, a gold, an aluminum and a nickel. 21.A camera comprising a display device according to claim 19, wherein apart of the auxiliary wiring is located in the second substrate.
 22. Acamera comprising a display device according to claim 19, wherein theauxiliary wiring is electrically connected to the current supply linevia a conductive material.
 23. A camera comprising a display devicecomprising: a first substrate; a light emitting element over the firstsubstrate: a first electrode; a second electrode adjacent to the firstelectrode; and a light emitting material interposed between the firstelectrode and the second electrode; a current supply line over the firstsubstrate, electrically connected to the first electrode; an insulatinglayer over the light emitting element; a second substrate; and anauxiliary wiring adjacent to the second substrate, wherein the auxiliarywiring is electrically connected to the first electrode via the currentsupply line, and wherein the insulating layer is located between thecurrent supply line and the auxiliary wiring.
 24. A camera comprising adisplay device according to claim 23, wherein the auxiliary wiringcomprises a metal selected from the group consisting of a copper, asilver, a gold, an aluminum and a nickel.
 25. A camera comprising adisplay device according to claim 23, wherein a part of the auxiliarywiring is located in the second substrate.
 26. A camera comprising adisplay device according to claim 23, wherein the auxiliary wiring iselectrically connected to the current supply line via a conductivematerial.
 27. A camera comprising a display device according to claim23, wherein the insulating layer is a resin material.
 28. A cameracomprising a display device according to claim 27, wherein the resinmaterial comprises a moisture absorbent material.
 29. A cameracomprising a display device according to claim 23, wherein theinsulating layer is a passivation film.
 30. A camera comprising adisplay device comprising: a first substrate; a light emitting elementover the first substrate: a first electrode; a second electrode adjacentto the first electrode; and a light emitting material interposed betweenthe first electrode and the second electrode; a current supply line overthe first substrate, electrically connected to the first electrode; aninsulating layer over the light emitting element; a second substrate;and an auxiliary wiring adjacent to the second substrate, wherein theauxiliary wiring is electrically connected to the first electrode viathe current supply line, and wherein the first substrate is locatedbetween the current supply line and the auxiliary wiring.
 31. A cameracomprising a display device according to claim 30, wherein the auxiliarywiring comprises a metal selected from the group consisting of a copper,a silver, a gold, an aluminum and a nickel.
 32. A camera comprising adisplay device according to claim 30, wherein a part of the auxiliarywiring is located in the second substrate.
 33. A camera comprising adisplay device according to claim 30, wherein the auxiliary wiring iselectrically connected to the current supply line via a conductivematerial.
 34. A camera comprising a display device according to claim30, wherein the insulating layer is a resin material.
 35. A cameracomprising a display device according to claim 34, wherein the resinmaterial comprises a moisture absorbent material.
 36. A cameracomprising a display device according to claim 30, wherein theinsulating layer is a passivation film.
 37. A personal computercomprising a display device comprising: a first substrate; a lightemitting element over the first substrate: a first electrode; a secondelectrode adjacent to the first electrode; and a light emitting materialinterposed between the first electrode and the second electrode; acurrent supply line over the first substrate, electrically connected tothe first electrode; a second substrate; and an auxiliary wiringadjacent to the second substrate, wherein the auxiliary wiring iselectrically connected to the first electrode via the current supplyline in a first connecting portion, and wherein the auxiliary wiring iselectrically connected to the first electrode via the current supplyline in a second connecting portion.
 38. A personal computer comprisinga display device according to claim 19, wherein the auxiliary wiringcomprises a metal selected from the group consisting of a copper, asilver, a gold, an aluminum and a nickel.
 39. A personal computercomprising a display device according to claim 19, wherein a part of theauxiliary wiring is located in the second substrate.
 40. A personalcomputer comprising a display device according to claim 19, wherein theauxiliary wiring is electrically connected to the current supply linevia a conductive material.
 41. A personal computer comprising a displaydevice comprising: a first substrate; a light emitting element over thefirst substrate: a first electrode; a second electrode adjacent to thefirst electrode; and a light emitting material interposed between thefirst electrode and the second electrode; a current supply line over thefirst substrate, electrically connected to the first electrode; aninsulating layer over the light emitting element; a second substrate;and an auxiliary wiring adjacent to the second substrate, wherein theauxiliary wiring is electrically connected to the first electrode viathe current supply line, and wherein the insulating layer is locatedbetween the current supply line and the auxiliary wiring.
 42. A personalcomputer comprising a display device according to claim 41, wherein theauxiliary wiring comprises a metal selected from the group consisting ofa copper, a silver, a gold, an aluminum and a nickel.
 43. A personalcomputer comprising a display device according to claim 41, wherein apart of the auxiliary wiring is located in the second substrate.
 44. Apersonal computer comprising a display device according to claim 41,wherein the auxiliary wiring is electrically connected to the currentsupply line via a conductive material.
 45. A personal computercomprising a display device according to claim 41, wherein theinsulating layer is a resin material.
 46. A personal computer comprisinga display device according to claim 45, wherein the resin materialcomprises a moisture absorbent material.
 47. A personal computercomprising a display device according to claim 41, wherein theinsulating layer is a passivation film.
 48. A personal computercomprising a display device comprising: a first substrate; a lightemitting element over the first substrate: a first electrode; a secondelectrode adjacent to the first electrode; and a light emitting materialinterposed between the first electrode and the second electrode; acurrent supply line over the first substrate, electrically connected tothe first electrode; an insulating layer over the light emittingelement; a second substrate; and an auxiliary wiring adjacent to thesecond substrate, wherein the auxiliary wiring is electrically connectedto the first electrode via the current supply line, and wherein thefirst substrate is located between the current supply line and theauxiliary wiring.
 49. A personal computer comprising a display deviceaccording to claim 48, wherein the auxiliary wiring comprises a metalselected from the group consisting of a copper, a silver, a gold, analuminum and a nickel.
 50. A personal computer comprising a displaydevice according to claim 48, wherein a part of the auxiliary wiring islocated in the second substrate.
 51. A personal computer comprising adisplay device according to claim 48, wherein the auxiliary wiring iselectrically connected to the current supply line via a conductivematerial.
 52. A personal computer comprising a display device accordingto claim 48, wherein the insulating layer is a resin material.
 53. Apersonal computer comprising a display device according to claim 52,wherein the resin material comprises a moisture absorbent material. 54.A personal computer comprising a display device according to claim 48,wherein the insulating layer is a passivation film.
 55. A portabletelephone comprising a display device comprising: a first substrate; alight emitting element over the first substrate: a first electrode; asecond electrode adjacent to the first electrode; and a light emittingmaterial interposed between the first electrode and the secondelectrode; a current supply line over the first substrate, electricallyconnected to the first electrode; a second substrate; and an auxiliarywiring adjacent to the second substrate, wherein the auxiliary wiring iselectrically connected to the first electrode via the current supplyline in a first connecting portion, and wherein the auxiliary wiring iselectrically connected to the first electrode via the current supplyline in a second connecting portion.
 56. A portable telephone comprisinga display device according to claim 55, wherein the auxiliary wiringcomprises a metal selected from the group consisting of a copper, asilver, a gold, an aluminum and a nickel.
 57. A portable telephonecomprising a display device according to claim 55, wherein a part of theauxiliary wiring is located in the second substrate.
 58. A portabletelephone comprising a display device according to claim 55, wherein theauxiliary wiring is electrically connected to the current supply linevia a conductive material.
 59. A portable telephone comprising a displaydevice comprising: a first substrate; a light emitting element over thefirst substrate: a first electrode; a second electrode adjacent to thefirst electrode; and a light emitting material interposed between thefirst electrode and the second electrode; a current supply line over thefirst substrate, electrically connected to the first electrode; aninsulating layer over the light emitting element; a second substrate;and an auxiliary wiring adjacent to the second substrate, wherein theauxiliary wiring is electrically connected to the first electrode viathe current supply line, and wherein the insulating layer is locatedbetween the current supply line and the auxiliary wiring.
 60. A portabletelephone comprising a display device according to claim 59, wherein theauxiliary wiring comprises a metal selected from the group consisting ofa copper, a silver, a gold, an aluminum and a nickel.
 61. A portabletelephone comprising a display device according to claim 59, wherein apart of the auxiliary wiring is located in the second substrate.
 62. Aportable telephone comprising a display device according to claim 59,wherein the insulating layer is a resin material.
 63. A portabletelephone comprising a display device according to claim 62, wherein theresin material comprises a moisture absorbent material.
 64. A portabletelephone comprising a display device according to claim 59, wherein theauxiliary wiring is electrically connected to the current supply linevia a conductive material.
 65. A portable telephone comprising a displaydevice according to claim 59, wherein the insulating layer is apassivation film.
 66. A portable telephone comprising a display devicecomprising: a first substrate; a light emitting element over the firstsubstrate: a first electrode; a second electrode adjacent to the firstelectrode; and a light emitting material interposed between the firstelectrode and the second electrode; a current supply line over the firstsubstrate, electrically connected to the first electrode; an insulatinglayer over the light emitting element; a second substrate; and anauxiliary wiring adjacent to the second substrate, wherein the auxiliarywiring is electrically connected to the first electrode via the currentsupply line, and wherein the first substrate is located between thecurrent supply line and the auxiliary wiring.
 67. A portable telephonecomprising a display device according to claim 66, wherein the auxiliarywiring comprises a metal selected from the group consisting of a copper,a silver, a gold, an aluminum and a nickel.
 68. A portable telephonecomprising a display device according to claim 66, wherein a part of theauxiliary wiring is located in the second substrate.
 69. A portabletelephone comprising a display device according to claim 66, wherein theauxiliary wiring is electrically connected to the current supply linevia a conductive material.
 70. A portable telephone comprising a displaydevice according to claim 66, wherein the insulating layer is a resinmaterial.
 71. A portable telephone comprising a display device accordingto claim 70, wherein the resin material comprises a moisture absorbentmaterial.
 72. A portable telephone comprising a display device accordingto claim 66, wherein the insulating layer is a passivation film.